Estimate, the royal horse who has made headlines around the world for good reasons and bad, turned in an anonymous performance in the Goodwood Cup, finishing last of eight as the 2-1 favourite. It may yet prove to be the final outing of her career, as connections were left with no clear plan for the winner of last year’s Gold Cup at Royal Ascot.

While she has thrived on fast surfaces in the past, she looked distinctly uneasy in Thursday’s race and the general view is that she did not enjoy the experience of racing downhill on such a dry surface. Asked if she was sound after her exertions here, her trainer, Sir Michael Stoute, responded: “We’ll see tomorrow”.

John Warren, the Queen’s racing manager, reported the views of Estimate’s jockey, Ryan Moore. “Ryan said she was never happy, never confident on the track, right from the minute she jumped off. And probably, like when she ran here once before, the track just doesn’t suit her. We were hoping that was just a one-off but she was never in a rhythm, never moving well.

“[Moore] wondered whether she was in season but Michael said he didn’t think so. So I think everyone settled on the track [as the explanation].”

The stewards ordered that Estimate be subjected to a urine test, as they often do with disappointing favourites. It was likely, in any case, that Estimate would be tested after running here, because of the fact that she famously tested positive for a banned substance, morphine, after her previous run, when second at Royal Ascot.

Given our present state of knowledge about the morphine cases, which we are told have resulted from a batch of contaminated feed, Estimate and the six other horses to have tested positive seem enormously unlucky to have been affected. One reporter asked Warren if the fact of having had morphine in her system last month might have affected her effort here; he looked shocked by the suggestion and dismissed the possibility.

A harder question to answer was what Estimate does now. Had she run well here, the Irish St Leger was a possibility, the Melbourne Cup another, but Warren seemed much less keen on those ambitious targets after the race.

The staying contest on Champions’ Day at Ascot in October would be a target if good ground could be guaranteed but it is likely to be soft. “The options are limited, so we’ll just have to go and get our heads around it and see what the Queen thinks,” Warren sighed.

Stoute fielded three other runners later in the day and all were beaten, though his horses have been faring well in recent days and he had a winner here on Wednesday. The Newmarket trainer then withdrew two of the three he had entered for Friday’s card, citing the fast going as the reason in both cases.

Estimate’s presence may have been a critical distraction for another horse with a high-profile owner, Michael Owen’s Brown Panther. His jockey, Richard Kingscote, said: “Every time I got in behind Estimate, he latched onto her. I couldn’t get him to settle.”

Having won this race last year, Brown Panther faded into third as the race was won by Godolphin’s Cavalryman, who is having a fine season at the age of eight, notching his third success since March. He provided another veteran, Kieren Fallon, with a first Goodwood Cup at the age of 49 and the pair may reunite for the Melbourne Cup in November.

Earlier, almost the entire crowd had been entranced by the unexpected presence of Tom Cruise, who gamely handed out the prize for the charity race and then spent half an hour covering the 100 yards back to the grandstand, posing for selfies with grinning fans every step of the way. Cruise was a guest of Lord March, whose family own the course, and he was chaperoned by Harry Herbert, racing manager to many other rich and famous types.

History does not record, yet, whether Herbert was able to persuade the Hollywood star to buy a leg of a well-bred yearling but a game effort was doubtless made. Herbert reported that Cruise picked at least one winner in Shagah. “He loved the name. He’s had a great time, he’s loving it.”